1. Technical Field
The present invention generally relates to electrical terminal assemblies. More particularly, the present invention relates to audio signal terminals for connections to loudspeakers.
2. Related Art
While significant improvements have been made in the development of high power loudspeakers, alternative solutions that utilize existing loudspeakers have been considered because of increased costs associated with such improved loudspeakers. These alternative solutions have involved the connecting of the loudspeakers in series or in parallel for enhanced performance. The loudspeakers are connected to an audio signal source, which may be a stereo receiver, an amplifier, etc. As is generally understood, a series connection of multiple loudspeakers increases the load impedance, resulting in a more efficient operation of the audio signal source. However, with the increase in load impedance, there is a decrease in the voltage applied to each loudspeaker and a consequential decrease in the audio output of the same. On the other hand, parallel connections decrease the load impedance, and while each loudspeaker is applied a constant voltage level, current draw on the audio signal source increases.
In addition to individual loudspeakers having single voice coils, recent advances in loudspeakers, particularly in woofers and subwoofers, have introduced the use of multiple voice coils in a single loudspeaker. Dual voice coil subwoofers, as are known in the art, have two separate windings mounted to a common bobbin and cone. Such loudspeakers are frequently used in car audio applications for increased flexibility in wiring. While power handling levels, frequency response, and other parameters remain the same whether connected in series or in parallel, the impedance “seen” by the audio signal source changes.
To enable multiple loudspeakers or multiple voice coil elements in a single loudspeaker to be easily connected in parallel or in series, devices such as the terminal block disclosed in U.S. Pat. No. 6,656,000 to Abdo have been developed. The Abdo device has one embodiment that was essentially a pair of metallic blocks, a first block being electrically connected to a positive line from the audio signal source and a second block being electrically connected to a negative line from the audio signal source. The first block includes a pair of output terminals to be connected to the respective one of positive wires of the loads (voice coil element). The second block likewise includes a pair of output terminals to be connected to the respective one of negative wires of the loads. Such first embodiment is operative to connect the loads in parallel. A second embodiment includes essentially the same components, but includes only one output terminal for each block. Thus, the positive wire of one of the loads is connected to the first block, the negative wire of the one of the loads is connected to the positive wire of the other load, and the negative wire of the other load is connected to the second block, connecting the loads in series.
As will be appreciated by an artisan having ordinary skill in the art, the Abdo device and other like devices essentially provides an accessible central junction for connecting the audio signal source and the wires of the loads. However, such prior devices are deficient in that it is still necessary to handle the actual wires of the loads to alter the configuration between series wiring and parallel wiring. Additionally, it is necessary to substitute different terminal blocks to switch between series wiring and parallel wiring. One major difficulty experienced by consumers in altering the configuration of loudspeakers is the clutter associated with handling the wires, and being unable able to ascertain whether the proper connections have been made. Therefore, there is a need in the art for an improved terminal assembly which can more readily switch the wiring configuration of electrical loads from parallel to series, and vice versa.